Reactive oxygen species-responsive miR-210 regulates proliferation and migration of adipose-derived stem cells via PTPN2.

Hypoxia enhances the proliferation and migration of adipose-derived stem cells (ASCs) via the generation of reactive oxygen species (ROS). Therefore, this study primarily investigated whether or not ROS generation could regulate microRNA-210 (miR-210) expression, and increase proliferation/migration of ASCs. In addition, we tried to identify the signaling pathways involved in miR-210 upregulation and the direct target genes of miR-210 that mediate these functions. Various sources of ROS generation such as hypoxia, antimycin, rotenone, and platelet-derived growth factor (PDGF)-BB upregulated miR-210 expression, and increased the proliferation/migration of ASCs. There is a positive feed-forward loop between ROS generation and miR-210, and miR-210 itself increases ROS generation by downregulation of iron-sulfur cluster scaffold homolog 2 (ISCU2). Although hypoxia-inducible factor-1α was not involved in miR-210 expression, pharmacological or small interfering RNA (siRNA)-driven inhibition of Akt and ERK1/2 molecules reduced miR-210 expression. Transfection of siRNAs of NF-κB and Elk1 also reduced miR-210 expression, indicating that these signaling pathways mediate miR-210 upregulation. Protein tyrosine phosphatase, non-receptor type 2 (PTPN2) was selected for miR-210 target gene, and it was downregulated by ROS generators or miR-210 mimic treatment. PTPN2 was first proven to be a direct miR-210 target in luciferase activity assay, and pharmacological inhibition or overexpression of PTPN2 regulated the proliferation and migration of ASC. In conclusion, ROS generation from diverse sources induces miR-210 expression in ASCs via PDGFR-β, Akt and ERK pathways. Transcription of miR-210 expression is regulated by NF-κB and Elk1, and miR-210 increases the proliferation and migration of ASCs via ISCU2 and PTPN2 downregulation.